Mahabharata 7.16.40

7.16.40

eṣa ca bhrātṛbhiḥ sārdhaṃ suśarmāhvayate raṇe |
vadhāya sagaṇasyāsya māmanujñātumarhasi || 40 ||

If, again, we succeed in achieving in battle feats the most difficult of accomplishment in the world, we shalt then, without doubt, obtain the most desirable regions. Having said these words, O king, those heroes then marched to battle, summoning Arjuna towards the southern part of the field. That tiger among men, and subjugator of hostile cities, Arjuna, thus challenged by them, said these words unto king Yudhishthira the Just without any delay: 'Summoned, I never turn back. This is my fixed vow. These men, sworn to conquer or die, are summoning me, O king, to great battle. This Susarman here, with his brothers, summoneth me to battle. It behoveth thee to grant me permission for slaying him, with all his followers. O bull among men, I am unable to brook this challenge. I tell thee truly, know these foes to be (already) slain in battle.'